000 AXNT20 KNHC 181801 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON NOV 18 2013 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURE... THE GALE CENTER HAS BEEN UPGRADED TO SUBTROPICAL STORM MELISSA AT 18/1500 UTC. SUBTROPICAL STORM MELISSA IS CENTERED NEAR 29.3N 53.6W AT 18/1500 UTC OR ABOUT ABOUT 605 NM E-SE OF BERMUDA MOVING NW 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. BROAD AREA OF ACTIVITY ASSOCIATED WITH THE DISSIPATING OCCLUDED FRONT/SUBTROPICAL STORM COVERED IN THE ATLANTIC SECTION BELOW. PLEASE SEE LATEST PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC AND THE FULL FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 8N13W AND CONTINUES TO 5N21W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 5N34W TO 8N46W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 1N-3N E OF 5W TO ACROSS THE PRIME MERIDIAN...FROM 3N-10N BETWEEN 14W-27W...AND FROM 9N-11N BETWEEN 32W-43W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER TROUGH WELL N OF THE DISCUSSION AREA DRAPES A COLD FRONT AT 18/1500 UTC JUST INLAND ALONG THE N GULF COAST FROM MOBILE ALABAMA TO HOUSTON TEXAS WITH A PRE-FRONTAL SURFACE TROUGH EXTENDING FROM TALLAHASSEE FLORIDA ACROSS THE MISSISSIPPI DELTA OF LOUISIANA ALONG 29N92W TO 27N96W. SCATTERED TO HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS ARE N OF 28N TO INLAND OVER THE N GULF COAST TO THE COLD FRONT. A BROAD UPPER RIDGE ANCHORED OVER THE YUCATAN PENINSULA IS GIVING THE GULF WATERS WESTERLY FLOW ALOFT. A WEAK SURFACE TROUGH IS IN THE SW GULF EXTENDING FROM 23N93W TO THE COAST OF MEXICO. ISOLATED SHOWERS ARE POSSIBLE OVER THE W GULF S OF 28N W OF 94W. COLD FRONT WILL MOVE INTO THE GULF WATERS THIS AFTERNOON AND EXTEND FROM TAMPA BAY TO NE MEXICO TUE THEN WEAKEN FROM SW FLORIDA TO THE S TEXAS COAST WED AND THU BEFORE DISSIPATING FRI. CARIBBEAN SEA... THE CARIBBEAN IS DOMINATED BY A LARGE UPPER RIDGE ANCHORED OVER THE YUCATAN PENINSULA NEAR 18N89W. WATER VAPOR IMAGERY CONTINUES TO SHOW DRY STABLE AIR ALOFT ACROSS THE ENTIRE CARIBBEAN THIS AFTERNOON. HOWEVER...SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS ARE S OF HAITI FROM 15N-18N BETWEEN 72W-75W. NE TO E TRADE WINDS ARE BANKING ISOLATED LOW LEVEL SHOWERS WITHIN 45 NM ALONG THE COAST OF COSTA RICA AND PANAMA W OF 81W AND DOTTING THE E CARIBBEAN FROM 12N-17N E OF 68W TO OVER THE LESSER ANTILLES. GENTLE TO MODERATE TRADE WINDS WILL PREVAIL ACROSS MOST OF THE REGION THROUGH FRI. ...HISPANIOLA... ALTHOUGH THE WATER VAPOR IMAGERY SHOWS DRY STABLE AIR ALOFT...NE SURFACE FLOW IS GENERATING POSSIBLE ISOLATED LOW LEVEL SHOWERS ACROSS THE THE MOUNTAIN REGIONS OF HISPANIOLA. THIS NE SURFACE FLOW AND ACCOMPANYING SHOWERS WILL PERSIST THROUGH TONIGHT. THE FLOW WILL THEN WEAKEN ON TUE DIMINISHING SHOWERS THROUGH THE END OF THE WEEK. ATLANTIC OCEAN... THE UPPER RIDGE ANCHORED OVER THE YUCATAN PENINSULA EXTENDS OVER THE W ATLC W OF 70W WHILE A WEAKENING SURFACE RIDGE COVERS THE SAME AREA ANCHORED WELL N OF THE DISCUSSION AREA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 45 NM OF LINE FROM CENTRAL FLORIDA COAST NEAR 27N80W TO BEYOND 32N77W. AN UPPER TROUGH COVERS THE CENTRAL ATLC N OF 15N BETWEEN 50W-65W SUPPORTING A DISSIPATING FRONTAL SYSTEM AND THE NEWLY UPGRADED SUBTROPICAL STORM MELISSA. AN UPPER RIDGE TO THE E EXTENDING FROM THE TROPICS NEAR 14N40W TO BEYOND 32N39W PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 16N-22W BETWEEN 44W-53W AND N OF 22N BETWEEN 43W-60W. A SURFACE TROUGH IS E OF THE LESSER ANTILLES EXTENDING FROM 16N57W TO 12N58W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 14N-16N BETWEEN 55W-58W. A SURFACE RIDGE DOMINATES THE E ATLC ANCHORED BY A 1031 MB HIGH OVER THE AZORES. COLD FRONT WILL MOVE OFF NE FLORIDA TONIGHT AND WILL REACH FROM 31N71W TO CENTRAL FLORIDA TUE MORNING THEN FROM 32N61W TO CENTRAL FLORIDA WED MORNING THEN BECOME DIFFUSE ALONG 27N THU. SURFACE RIDGE WILL BUILD IN BEHIND THE FRONT TUE THROUGH FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW